FFI::Platypus object is attached to foreign functions using 'attach'
method call. These calls are in lib/Geo/GDAL/FFI.pm.

parse_h.pl is a program to create these calls (wrapped in eval{};)
from C/C++ header files. Currently it is used for the following header
files:

gcore/gdal.h
ogr/ogr_api.h
ogr/ogr_srs_api.h
apps/gdal_utils.h

To update lib/Geo/GDAL/FFI.pm run parse_h.pl with those files as
arguments and paste the output to lib/Geo/GDAL/FFI.pm.

Some foreign functions that are defined in header files

port/*.h
ogr/ogr_core.h

are attached using manually written calls in lib/Geo/GDAL/FFI.pm.